1. Field of the Invention
The present invention relates to an electronic image printing method in which: an electronic image formed with toner by an electronic image forming apparatus is transferred to a piece of transfer sheet; and the electronic image is transferred again to a T-shirt, a piece of synthetic leather, natural leather, plastic material, metal, glass, ceramic material, wood, paper and any other material.
2. Related Arts
As a recent tendency commercial products have been individualized to meet individual tastes, and accordingly it is required that a variety of commercial products be marketed in small lots. In order to suppress the rise of manufacturing cost it is of great concern that patterns be printed easily on T-shirts or other cloth products at a reduced cost. To meet such demand use is made of an electronic image forming apparatus to effect required printings on T-shirts or other cloth products by forming desired different images on pieces of thermal-transfer paper and by applying a relatively high pressure to laminations each of the thermal-transfer paper and the T-shirt at a relatively high temperature.
A desired image can be easily formed with the aid of a computer, and the so formed image is outputted from the electronic image forming apparatus to be transferred to a piece of thermal-transfer paper, as proposed in Japanese Patent 3-48860(A). According to the invention titled xe2x80x9cmethod of forming toner image receptorsxe2x80x9d a desired toner image is put on a piece of transfer paper whose surface layer is adherent to toner; the transfer paper is laid on an image receptor with the toner image facing the image receptor; and the transfer paper is separated from the underlying image receptor while the transfer paper is heated above the toner softening temperature, thus leaving the toner image on the image receptor.
Another conventional art is disclosed in a Japanese Patent Application filed on Mar. 11, 1993, claiming a patent to the invention titled xe2x80x9cMethod of Transferring Pressure-Sensitive Images Instantaneously, Using Image Forming Carriers Provided by an Electronic Image Forming Apparatusxe2x80x9d. According to the claimed invention a substrate, an image carrier film bearing an image formed with toner, a cover coating and a pressure-sensitive coating are jointed on top of each other; the resulting lamination is put on an object to which the image is to be transferred, with the pressure-sensitive coating facing the object; the substrate is removed from the image carrier film; a rub-and-push is applied to the toner image via the overlying image carrier; and finally the image carrier is removed to leave the toner image on the object.
In transferring an electronic image from the transfer paper to a T-shirt or any other object undesired parts of the transfer paper such as the image-surrounding area are likely to be transferred to the T-shirt or cloth article. If an electronic image is transferred to a piece of colored cloth rather than a piece of white cloth, live color printing is almost impossible. Assuming that a rectangular piece of transfer paper has letters or patterns to be transferred to a piece of cloth, the parts of the background of the transfer paper which surround the letters or patterns are transferred to the piece of cloth, thus causing the printed images to be pleasing less in appearance than the originals.
In the hope of transferring letters or patterns exactly to a piece of cloth without lowering their live tones of colors the Japanese Patent 9-87980(A), published on Sep. 20, 1995 discloses xe2x80x9cElectronic Image Printing Method and Thermal-Transfer Sheetxe2x80x9d. According to the Electronic Image Printing Method a sheet of lamination A comprising a substrate, a mold-release layer and a polyvinyl alcohol layer (PVA layer) or polyester resin layer jointed to top of each other, and another sheet of lamination B comprising a substrate, a mold-release layer, an adhesive layer and a color layer joined to top of each other are prepared; desired letters or patterns are formed on one of these laminations A and B with toner; these lamination A and B are laid on each other to sandwich the toner images therebetween to be pressed at an elevated temperature; and the laminations A and B are so separated from each other as to leave the color layer and overlying adhesive layer on the lamination A; the remaining composite lamination is applied to a T-shirt to remove the substrate-and-mold-release layer combination; and the remaining composite lamination is pressed at an elevated temperature; and finally the polyvinyl alcohol layer (PVA layer) or polyester resin layer is removed to leave the toner images, which are applied to the T-shirt via the color-and-adhesive composite lamination.
Presence of the color layer under the desired letters or patterns formed with toner prevents effectively the colors of the desired images from being adversely effected by the color of the T-shirt, thus providing the live colored prints on the T-shirt no matter what color the T-shirt may be of. The Electronic Image Printing Method, however, cannot be used in printing white letters or patterns on a piece of colored cloth because no white toner is available. Letters and patterns are often white or partly white, and such letters and patterns cannot be printed. Accordingly the kinds of letters and patterns to be printed are limited significantly.
According to the teaching of Japanese Patent 10-325087(A), an electronic image is transferred to a thick-colored thermal-transfer sheet, and the electronic image is cut out with a cutter to be transferred to an object. In printing desired white letters these letters are processed by a computer to provide data which represent their contours; the white letters are cut away automatically from the first thick-colored thermal-transfer sheet to be heat-pressed and transferred to another thermal-transfer sheet having a release layer jointed to its top; and finally the white letters are thermal-transferred from the second thermal-transfer sheet to a thick-colored object.
It is, however, difficult to cut a desired letter or pattern exactly from the thick-colored transfer sheet manually, and five-millimeter or smaller letters or patterns can be hardly cut out. Apparatus for computer-aided cutting, however, is inhibitively expensive, and therefore, the demand for printing at a low cost cannot be met.
In view of the above one object of the present invention is to provide an electronic image printing method permitting the quick transfer of electronic images from thick colored transfer sheets to desired thick-colored articles at a reduced cost, not requiring the manual or computer-aided cutting-out of desired images no matter what size the image may have, small or large.
The printing of white or milk white letters or patterns is permitted on pieces of colored cloth. Also, the printing of colored letters or patterns on white or milk white base areas, which are printed on pieces of colored cloth, is permitted.
First, a desired letter or pattern is formed on a piece of copying paper to provide a negative image of the desired letter or pattern with toner.
A piece of laminated sheet B comprising a substrate, a mold-release layer, an adhesive layer and a white (milk white) layer joined on top of each other is prepared.
The piece of copying paper is laid on the piece of laminated sheet B to be thermal-pressed together.
Removal of the copying paper from the underlying laminated sheet B permits the area of milk white layer-and-adhesive layer combination corresponding to the negative image to be taken apart from the underlying laminated sheet B, thus leaving the remaining area of milk white layer-and-adhesive layer combination corresponding to the positive image of the desired letter or pattern.
A piece of laminated sheet A comprising a substrate, a mold-release layer and a resin layer joined on top of each other is prepared, and the piece of laminated sheet A is laid on the so modified laminated sheet B to be pressed at an elevated temperature, thus allowing the positive image of milk white layer-and-adhesive layer combination to be transferred to the laminated sheet A.
The laminated sheet A having the positive image under is applied to a piece of colored cloth with the adhesive layer facing the colored cloth to be pressed together at an elevated temperature. Finally the laminated sheet A is removed from the piece of colored cloth, thus providing the piece of colored cloth having the desired white letter or pattern printed thereon.
Also, it is possible to print colored letters or patterns within a milk white base area, which is printed on a piece of colored cloth. The colored letters or patterns are printed on a piece of laminated sheet A with a color copier, a color laser printer or an ink-jet printer. On the other hand, a negative image of base is formed on a piece of copying paper with toner, and the copying paper is laid on a piece of laminated sheet B to be pressed at an elevated temperature. Removal of the copying paper leaves the positive image of the base on the laminated sheet B, which positive image of the base is composed of the milk white layer-and-adhesive layer. The laminated sheet A having the colored letters or patterns printed on its top is laid on the so modified laminated sheet B to be pressed at an elevated temperature. Removal of the laminated sheet A causes the base area of milk white layer-and-adhesive layer to leave the mold-release layer of the laminated sheet B. The laminated sheet A whose top has the colored letters or patterns in the base area of milk white-and-adhesive composite lamination is laid on a piece of colored cloth with the adhesive layer facing the colored cloth to be pressed together at an elevated temperature, thus allowing the colored letters or patterns along with the milk white base area to be transferred from the underlying mold-release layer to the piece of colored cloth. Thus, the piece of colored cloth having the colored letters or patterns printed on the milk white base area.
Alternatively a similar piece of colored cloth having colored letters or patterns printed on its milk white base area may be provided by color-printing the letters or patterns on the milk white layer of the laminated sheet B, although the transferring steps in the proceeding described above need be somewhat changed in the order.
Temperatures, pressures and lengths of time involved for pressing different composite laminations at elevated temperatures in the course of image-transfer are dependent on what kinds of material such laminated sheets are made.
Other objects and advantages of the present invention will be understood from the following description of preferred embodiments of the present invention, which are shown in accompanying drawings.